TEHRAN (Tasnim) - The future role of Syrian President Bashar al-Assad is a "red line" for the government delegation in peace talks in Geneva, the foreign minister said on the eve of their opening.

"The issues of the president and the regime are red lines for us and for the Syrian people," the official SANA news agency quoted Walid Muallem as saying shortly before his delegation arrived in the Swiss city of Montreux for the talks.

"Nobody can touch the presidency."

Muallem promised that the government delegation would make every effort to ensure the peace conference bore fruit, AFP reported.

"We are committed to working for the success of this conference so that it is the first step on the road to a dialogue between Syrians on Syrian soil," he said.

But he hit out at the UN organisers of the peace conference for their failure to invite a separate delegation from the government-tolerated opposition in Damascus which opposes the armed rebellion supported by the exiled National Coalition.

"The UN gave in to Western pressure by refusing to invite the national opposition," he charged.

The regime-tolerated National Coordination Body for Democratic Change said on Monday that it had turned down an invitation from the National Coalition to attend the peace talks as part of a single delegation.

It said its leader Hassan Abdel Azim had been invited to take part on Sunday by Coalition president Ahmad Jarba but had refused.